 public int[] twoSum(int[] nums, int target) {

        int[] index = new int[2]; //存储两个整数的下标
        for(int i = 0; i < nums.length-1; i++){
            for(int j = i+1; j < nums.length; j++){
                if(nums[i] + nums[j] == target){
                    index[0] = i;
                    index[1] = j;
                    return index;
                }
            }
        }
        return null;
}